Type of intelligent pumping unit

ABSTRACT

The invention discloses a new type of an intelligent pumping unit, including a counter weight box whereas a first driven sprocket is provided on a top inside of said counter weight box and a second driven sprocket is provided at a bottom inside of said counter weight box, and a pedestal whereas an electric motor and a reducer mounted thereto; the reducer, with a driving sprocket connected on its output shaft, is driven to rotate by the electric motor via a belt.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. § 119 to Chinese patent application 201620262871.5, filed on Mar. 31, 2016, the disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a new type of intelligent pumping unit, and to an invention of machinery and equipment.

BACKGROUND OF THE INVENTION

An oil well shall be extracted by power equipment in case the reservoir energy is less than the energy for self-overflow. And the extraction shall be continued for several years in general or even for several decades in case the time for continuous production is long. Thus, though the oil and gas may be extracted by many means, there are few extracting equipment that may meet the requirements of stability, reliability and long service life.

Over hundreds of years of development in oil and gas extraction, the reciprocating extraction has been widely accepted, mainly because it is most stable, reliable and economic and its mechanical life is able to meet the requirements of oil and gas extraction;

The equipment for reciprocating extraction consists of down-hole oil-well pump, sucker rod and pumping unit (e.g. the ground power equipment). The present development and invention mainly focus on the pumping unit, the ground power equipment for reciprocating extraction.

The core of the reciprocating extraction lie in the reciprocating motion of the oil-well pump seating at the bottom of the well, which is connected to the pumping unit (the ground power equipment) via the sucker rod resting in the shaft and is used to extract the down-hole oil to the ground by the reciprocating motion of the oil-well pump plunger driven by the pumping unit so as to realize the reciprocating oil extraction.

During the development of power equipment for reciprocating extraction from the beam pumping unit, a variety of models have been developed so far. However, these models are mainly divided into two types according to the manners, i.e. beam pumping unit and vertical pumping unit. Due to the mature and reliable technologies after hundreds of years of development, the beam pumping unit is the major power equipment for reciprocating oil and gas extraction. But there are fatal flaws that cannot be corrected or improved existing in this model: first, the fundamental mechanical structure decides the stroke length shorter than that of the vertical pumping unit, which will reduce the pump efficiency, shorten the service life of the down-hole pump and increase the energy consumption because the efficiency of the plunger pump is directly related to the stroke length; second, the load is smaller than that of the vertical pumping unit, failing to meet the demand of heavy-load oil well; third, the balance is poorer than that of the vertical pumping unit. In the reciprocating extraction, the counterweight of the equal load corresponding to the weight of the sucker rod shall be added in the extracting equipment for purpose of balance due to the heavy weight of the down-hole pump, in particularly the sucker rod with the length of over 1 km. However, compared with vertical pumping unit, the balance of the beam pumping unit is poorer, which will increase the energy consumption and equipment wear and shorten the mechanical life; fourth, its short stroke and small load, unable to meet the extraction demand of the oil well with high flow rate; last, the fundamental mechanical structure of the beam pumping unit decides that there are only three feasible stroke lengths and it is necessary to add the frequency converter or replace the roller to adjust the jig frequency, which means it is unable to deal with the real-time changes of the down-hole produzzction and it costs a lot of time and labors to adjust the frequency in the field even when the unit is shut down. Therefore, it is difficult to satisfy the dynamic extraction of digitized oil field.

Nowadays, when the oil industry is automated and digitized, the beam pumping unit is being phased out gradually, which also triggers an upsurge in vertical pumping unit research and development.

However, there are many requirements for the ground power equipment for reciprocating extraction in the aspects of stability, reliability, adaptability to severe filed environment, and long service life of the entire equipment. Although there are various types of vertical pumping units, only a few may meet the requirements and are accepted. For example, the long circular rack pumping unit driven by steel wire rope or rope-core belt and powered by permanent magnet motor is still under research and development because the service life of the steel wire rope or rope-core belt and the permanent magnet motor is unable to meet the requirements of stability, reliability and mechanical life.

Up to now, only the ROTAFLEX vertical pumping unit and the tower-type vertical pumping unit manufactured by Weatherford have been recognized by the market for years to a certain extent.

ROTAFLEX, invented in 1980s, has been promoted worldwide in the oil producing areas and has got a favorable reception in the market due to the adoption of sprocket-chain and load belt as the main driving components to ensure the mechanical life of the equipment as well as the excellent balance and long stroke length of the vertical pumping unit to save great energy and meet the requirements of the heavy-load and large-flow wells. However, the use of the unit reflects some problems, mainly consisting in the following aspects:

I. Although the load belt mitigate the impact of the mechanical reversing machine imposed on the down-hole rod pump and the equipment, the fundamental structure of the mechanical reversing mode decides that the operation of the machine does not conform to the operation features in physical kinematics, which is mainly presented in two aspects: one is the short reversing time and large inertial impact; the other is the uniform motion immediately after reversing direction that is non-conforming to the kinematical characteristics, resulting in the impact on the mechanical reversing machine caused by the heavy load and inertial impact arising from rush direction switch. Thus, it shortens the service life of the reversing machine, which will impact the service life of the unit and even the Christmas tree of the oil well;

II. The bearing structure of ROTAFLEX is that the reducer is hung with the counter weight box via chains and the sprocket is hung individually on the upper of the rack, which can barely bear heavy load unless the upper bearing, single chain and reducer are of sufficient strength. Thus, it is difficult to realize the heavy-load model with the polished rod load of more than 22 ton;

III. The inconvenient adjustment of stroke length and jig frequency is unfavorable for the dynamic field adjustment and unable to meet the requirements of dynamic self-adjustment, which can barely satisfy the dynamic extraction of digitized oil field.

IV. The unit is of good structure of the one-piece equipment. However, it cannot be repaired in case of component damage in the rack, which will not only affect the production but also increase the repair cost.

There are various defects existing in tower-type pumping units, for example, the steel rope-core belt can barely satisfy the service life of pumping unit in the oil and gas extraction, and it is difficult for the unit to meet the oil and gas production safety requirements.

SUMMARY OF THE INVENTION

The technical problem to be solved by the invention is to provide a new type of intelligent pumping unit to overcome defects mentioned above, overcome defects such as short stroke length, low pump efficiency, high energy consumption, short service life, poor balance and difficulty in situ repair and maintenance, have the most remarkable highlights of high intelligence, high cost-effectiveness, energy saving, wide loading range, and capabilities of bearing heavy load and of realizing real-time stepless adjustment of stroke length and jig frequency, and of satisfying the extraction needs for special reservoirs in certain oil fields.

The following technical scheme of the present invention is adopted to solve the above technical problems:

An intelligent pumping unit, including a counter weight box with a first driven sprocket provided on the top inside of said counter weight box, a second driven sprocket provided at a bottom inside of said counter weight box, and a pedestal with an electric motor and a reducer; the reducer, with a driving sprocket mounted on an output shaft, is driven to rotate by the electric motor via a belt.

In yet another embodiment, said pumping unit includes the pedestal with the electric motor and the reducer; the reducer, with the driving sprocket mounted on the output shaft, is driven to rotate by the electric motor via the belt.

In yet another embodiment, said second driven sprocket is connected to a driving sprocket via chain.

In yet another embodiment, said new type of intelligent pumping unit includes a rack with a roller, whereas the roller is winded up with a load belt, and mounted on a platform on a top of the rack.

Furthermore, a first end of said load belt is connected to the counter weight box and a second end of said load belt is connected to a sucker rod.

Furthermore, a transitional sprocket is mounted on the top inside of said rack, which is connected to the driving sprocket and the first driven sprocket via a chain.

The pumping unit described in the invention has the following advantages:

An energy-saving motor of the equipment is realized on the basis of accurate operation by motor programs and feedback and control for operation conditions. The unit is more suitable for operation features of down-hole rod pump that results in prolonged service life of the rod pump and postponed well-repair cycle; more accurate control for stroke length and jig frequency; full coverage of loading range; energy-saving, stable and reliable operation; long service life of complete equipment,;real-time operation condition control and real-time remote control.

The invention will now be detailed with reference to the drawings and embodiments.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a structure diagram of an intelligent pumping unit in the embodiment of the present invention;

In the diagram: 1: electric motor, 2:reducer, 3: driving sprocket, 6: transitional sprocket, 7: roller, 8: load belt, 9: sucker rod, 10: counter weight box, 11: first driven sprocket, and 12: second driven sprocket.

DESCRIPTION OF THE INVENTION

The Embodiment 1, as shown in FIG. 1, is a new type of intelligent pumping unit, including the pedestal mounted with the electric motor (1) and the reducer (2); the reducer (2), with the driving sprocket (3) mounted on the output shaft, is driven to rotate by the electric motor (1) via the belt.

Said intelligent pumping unit also includes the counter weight box (10) with the first driven sprocket (11) provided on the top inside of the counter weight box (10) and the second driven sprocket (12) provided at the bottom inside the box (10). And, the second driven sprocket (12) is connected to the driving sprocket (3) via a chain.

Said intelligent pumping unit also includes the rack with the roller (7), which is winded up with the load belt (8), mounted on the platform on the top of the rack. And the first end of the load belt (8) is connected to the counter weight box (10) and the second end is connected to the sucker rod (9).

The transitional sprocket (6) is mounted on the top inside of said rack, which is connected to the driving sprocket (3) and the first driven sprocket (11) via a chain.

Said intelligent pumping unit also includes an intelligent control system, which is provided in a control cabinet in a reasonable position adjacent to the motor (1).

Operating principle: first, setting up a control program according to the production capacity of an oil well, the control system controls the operation of the motor. And the motor drives the rotation of the reducer via the belt and the driving sprocket mounted in the output shaft of the reducer will rotate together. The rotation of the driving sprocket will drive the chain provided to rotate the second driven sprocket.

The above description is the example for the best embodiment of the invention; the parts that are not described in details shall be common knowledge for the people with ordinary skills in the art. Any equivalent transformation enlightened by the invention shall be covered with in the scope of protection for the invention. 

We claim:
 1. An intelligent pumping unit, comprising a counter weight box, wherein a first driven sprocket is provided on its top inside and a second driven sprocket is provided at a bottom inside of said box.
 2. The intelligent pumping unit according to claim 1, further comprising a pedestal mounted with an electric motor and a reducer; the reducer, with a driving sprocket connected on its output shaft, is driven to rotate by the electric motor via a belt.
 3. The intelligent pumping unit according to claim 2, wherein a second driven sprocket is connected with the driving sprocket via a chain.
 4. The intelligent pumping unit according to claim 2, wherein said pedestal is installed with a rack, whereas a roller mounted on a platform on the top of the rack, and the roller is winded up with a load belt.
 5. The load belt according to claim 4, wherein one end of said load belt is connected to the counter weight box and another end is connected to a sucker rod.
 6. The intelligent pumping unit according to claim 4, wherein a transitional sprocket is mounted on the top inside of the rack, whereas said transitional sprocket is connected to the driving sprocket and the first driven sprocket via the chain. 